1. Field of the Invention
The present invention relates to a data communication network system, more particularly, to a polling type network communication system in which a master station has a unit for registering transmission requests from slave stations and carrying out a polling in accordance with registered transmission requests, to improve an effective polling speed.
2. Description of the Related Art
In a data communication network system, a plurality of slave stations are sequentially communicated with a master station by a polling method, but sequential-polling method has the disadvantages of a slow response time and a low polling speed. Specific prior art will be described later with reference to the drawings.